Tinnitus rehabilitation device and method

ABSTRACT

A tinnitus method and device for providing relief to a person suffering from the disturbing effects of tinnitus is described. The method can be implemented entirely in software to spectrally modify an audio signal in accordance with a predetermined masking algorithm which modifies the intensity of the audio signal at selected frequencies. A predetermined masking algorithm is described which provides intermittent masking of the tinnitus wherein, at a comfortable listening level, during peaks of the audio signal the tinnitus is completely obscured, whereas during troughs the perception of the tinnitus occasionally emerges. In practice it has been found that such intermittent masking provides an immediate sense of relief, control and relaxation for the person, whilst enabling sufficient perception of the tinnitus for habituation and long term treatment to occur. Advantageously the predetermined masking algorithm is specifically tailored to the audiometric configuration of the person. For example, the masking algorithm may be partly tailored to the hearing loss characteristic of the person. A tinnitus rehabilitation device used in conjunction with a personal sound reproducing system is also described.

FIELD OF THE INVENTION

[0001] The present invention relates to a tinnitus rehabilitation deviceand method for providing relief and treatment to persons suffering fromthe disturbing effects of tinnitus and relates particularly, though notexclusively, to such a method and device that employs intermittentmasking of the tinnitus.

BACKGROUND TO THE INVENTION

[0002] Tinnitus is the perception of a sound in the absence of anycorresponding external sound. It is most commonly perceived as aringing, buzzing, whirring type sound, but can also be perceived as abeating, or pounding sensation. Around one third of people who sufferfrom tinnitus can be quite highly disturbed by it. Continuous perceptionof tinnitus can lead to insomnia, an inability to relax, state and traitanxiety, depression, and even suicide in extreme cases. Often closelyassociated with tinnitus is the perception of hyperacusis, which is agreat intolerance to external sounds, even the softer everyday sounds.This distressing condition can even occur as a precursor to tinnitus,and is thought to share the same underlying causes. Thus, everyreference to tinnitus in this document should be construed as includingthe phenomena of hyperacusis or other types of loudness discomfort.

[0003] There are very few effective treatment options available fortinnitus sufferers, with the vast majority only being advised that“you'll have to learn to live with it”. Most patients find that they canfar more readily ignore an external sound than their tinnitus. Onepalliative method has been to use hearing aid-style devices that producea band of noise to totally mask the perception of the tinnitus. Thisgives a sense of relief and control over the tinnitus in around half ofpatients, but usually has no long-term effect. The prohibitive cost(around A$1500) and aesthetic considerations limits the proportion ofsufferers for whom this is a viable measure. The presence of hearingloss for external sounds in the tinnitus region often means that themasking noise needs to be unpleasantly loud before the tinnitus can bemasked, and the noise is often judged to be not much better than thetinnitus itself.

[0004] In the past four years, a new understanding of theneurophysiological processes underlying tinnitus has been published,emphasising the role of the neural pathways in the emergence ofdistressing tinnitus and the possibility of using this neural plasticityto retrain its perception. This has been dubbed “Tinnitus RetrainingTherapy” or TRT. In this technique, patients are given intensivecounselling, and use noise generators at a volume that does notcompletely mask the tinnitus. Long term reductions in tinnitusdisturbance have been achieved in some patients, but it is usual forthis process to take at least 18 months of therapy before anysubstantial benefit occurs. TRT also offers very little immediate senseof relief from the tinnitus, and no relief from the associated sleepdisturbance and inability to relax.

[0005] The closest known prior art to the invention is the “SilentiaSet” developed by Starkey Corp., which is a pair of hearing aid deviceswhich wirelessly receive signals from a stereo system via an inductionloop under a pillow at bedtime. Recording of high frequency noise bands(“water sounds”), babble noise, traffic sounds and music have been usedto mask tinnitus using this system, however the high cost of theSilentia Set make it prohibitive for many sufferers.

[0006] Other prior art audiotherapeutic techniques using music are theTomatis Method developed by Alfred A. Tomatis, and Auditory IntegrationTraining. While neither method is designed for the treatment oftinnitus, the two techniques have some similarities in that they modifymusic for the treatment of auditory disorders. The Tomatis Methodemploys an “Electronic Ear” developed by Alfred Tomatis, (U.S. Pat. No.4,021,611). It has its origins from an extremely outdated model of howthe auditory system works, and has been widely debunked by audiologicalorganisations. Auditory Integration Training is based on the TomatisMethod, but-presents the music at extremely loud levels, that may resultin hearing damage, and importation of devices using this technique havebeen banned by the American Food and Drug Administration.

SUMMARY OF THE INVENTION

[0007] The present invention was developed with a view to providing amore effective rehabilitation technique and device for tinnitussufferers that is consistent with contemporary understandings of theunderlying pathology in the auditory system, of which tinnitus is asymptom.

[0008] Throughout this specification the term “comprising” is usedinclusively, in the sense that there may be other features and/or stepsincluded in the invention not expressly defined or comprehended in thefeatures or steps subsequently defined or described. What such otherfeatures and/or steps may include will be apparent from thespecification read as a whole.

[0009] According to one aspect of the present invention there isprovided a tinnitus rehabilitation method for providing relief to aperson suffering from the disturbing effects of tinnitus, the methodcomprising:

[0010] providing an audio signal spectrally modified in accordance witha predetermined masking algorithm designed to modify the intensity ofthe audio signal at selected frequencies whereby, in use; when-thespectrally modified audio signal is heard by the person it providessignificant masking of the tinnitus.

[0011] Preferably the method further comprises the steps of:

[0012] transmitting, using a computer, data representing an audiogram ofthe person suffering from tinnitus;

[0013] processing said audiogram data at a remote location and producingrequired equalisation response data based on said audiogram data usingsaid predetermined masking algorithm;

[0014] receiving, using a computer, said required equalisation responsedata; and,

[0015] combining said required equalisation response data with audiodata representing said audio signal to produce said spectrally modifiedaudio signal.

[0016] According to a second aspect of the invention there is provided amethod of using a computer to provide access to a predetermined maskingalgorithm used in tinnitus rehabilitation, for providing relief to aperson suffering from the disturbing effects of tinnitus, the methodcomprising:

[0017] receiving on-line, from a user, data representing an audiogram ofthe person suffering from tinnitus;

[0018] processing said audiogram data using said predetermined maskingalgorithm to produce required equalisation response data based on saidaudiogram data; and,

[0019] transmitting said required equalisation response data to theuser.

[0020] According to a another aspect of the present invention there isprovided a tinnitus rehabilitation sound recording for providing reliefto a person suffering from the disturbing effects of tinnitus, the soundrecording comprising:

[0021] an audio signal spectrally modified in accordance with apredetermined masking algorithm designed to modify the intensity of theaudio signal at selected frequencies whereby, in use, when the soundrecording is heard by the person it provides significant masking of thetinnitus.

[0022] Preferably the predetermined masking algorithm providesintermittent masking of the tinnitus wherein at a comfortable listeninglevel, during peaks of the audio signal the tinnitus is substantiallycompletely obscured, whereas during troughs the perception of thetinnitus occasionally emerges. In practice it has been found that suchintermittent masking can provide an immediate sense of relief, controland relaxation for the person, whilst enabling sufficient perception ofthe tinnitus for habituation and long term treatment to occur.

[0023] Typically said predetermined masking algorithm is designed tomodify the intensity of the audio signal across substantially the fullspectral range of the audio signal. Preferably said audio signal is ahighly dynamic signal in which the spectral content and intensityconstantly varies over time. Most preferably the audio signal is a musicsignal. However other types of signals including speech or noise mightalso be employed.

[0024] Advantageously said predetermined masking algorithm is at leastpartly tailored to the audiometric configuration of the person.Typically said predetermined masking algorithm is partly tailored to thehearing loss characteristic of the person. Preferably the spectralqualities of the audio signal are modified by the masking algorithm soas to provide a relatively equal sensation level across a major portionof the audio spectrum in both ears. Typically said predetermined maskingalgorithm also incorporates a set of calibration figures such as forconverting dB HL (Hearing Level) to dB SPL (Sound Pressure Level), or tocorrect for the presence of various coupling system types.

[0025] According to a still further aspect of the present inventionthere is provided a tinnitus rehabilitation device for providing reliefto a person suffering from the disturbing effects of tinnitus the devicecomprising:

[0026] signal filtering means adapted to spectrally modify an audiosignal in accordance with a predetermined masking algorithm designed tomodify the intensity of the audio signal at selected frequencieswhereby, in use, when the spectrally modified audio signal is heard bythe person it provides significant masking of the tinnitus.

[0027] Preferably said signal filtering means is a programmable signalfiltering means whereby, in use, the device can be programmed with apredetermined masking algorithm adapted to the particular needs of theindividual suffering from tinnitus.

[0028] In a preferred embodiment of the device the predetermined maskingalgorithm is of the form:

REQ=M(SPL+ELC(0.25,0.5,1,2,3,4,6,8,10,12 kHz)−Baseline)

[0029] where REQ=Required equalisation response of the TinnitusRetraining Protocol

Baseline=0.5 (A−B)+B

[0030] A=mean dB SPL at the two adjacent greatest hearing lossfrequencies in the greatest hearing loss ear

[0031] B=mean dB SPL at the two adjacent least hearing loss frequenciesin the least hearing loss ear

[0032] SPL=hearing thresholds (in dB HL) converted to dB SPL

[0033] ELC=transfer values for 40 Phon Equal Loudness Contours

[0034] M=gain multiplier=0.3 to 0.95

Preferably M=0.4

[0035] However, in an alternative software embodiment of the invention,the mathematical algorithm by which the individual prescription of theaudio signal is calculated may differ from the above algorithm. Suchother embodiments of the invention would be consistent with theessential clinical technique that is intended to provide a modificationof the intensity of an audio signal to account for hearing levelsspecifically for the relief and/or treatment of tinnitus andhyperacusis.

[0036] Preferably the device is employed in conjunction with a personalmusic player (PMP) and has an input adapted to connect to the audiooutput headphone jack on the PMP. Preferably the device has a standardheadphone jack to which a standard PMP headphone can be connected.Alternately, a transmitter may be used to transmit a signal to awireless type of receiver that may be placed in the ear canal, conchaarea, behind the ear, or some other area relatively close to the ear.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to facilitate a more detailed understanding of thenature of the invention preferred embodiments of the tinnitusrehabilitation device and method will now be described in detail, by wayof example only, with reference to the accompanying drawing in which:

[0038]FIG. 1 is a graphical representation of the long-term spectra ofboth a music recording and a typical prior art tinnitus masker;

[0039]FIG. 2 is a graphical representation of a typical patient'shearing thresholds and their required equalisation curve calculatedusing a first embodiment of the masking algorithm;

[0040]FIG. 3 is a schematic diagram graphically illustratingintermittent tinnitus masking with music;

[0041]FIG. 4 is a graphical representation of the same patient's hearingthresholds and their required equalisation curves calculated using asecond embodiment of the masking algorithm;

[0042]FIG. 5 is a schematic block diagram of a possible embodiment of atinnitus rehabilitation device in accordance with the invention; and

[0043]FIGS. 6 and 7 are flowcharts illustrating a preferred method ofproviding a tinnitus rehabilitation sound recording in accordance withthe present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0044] Tinnitus masking can be broadly defined as the obscuring oftinnitus perception with an external sound. Hearing aids can provide aneffective form of environmental noise masking for only around 10% ofsufferers. The most reliable audiometric measure of the effectiveness oftinnitus maskers is the amount of noise required to just mask anindividual's tinnitus. This measure is known as the Minimum MaskingLevel (“MML”). Amongst the most important criteria for successfulmasking is that the acceptability of a masking stimulus is inverselyproportional to its MML, and that the stimulus needs to be asufficiently pleasant substitute for the tinnitus. In the presentinventor's clinical practice, several sufferers have reported attemptingto use music to find relief from their tinnitus, but often found thatthe volume required to mask their tinnitus was unacceptably high. Mostof these persons tended to have a steeply sloping hearing losscharacteristic, and a tinnitus pitch which closely corresponded with theedge of the maximal hearing loss frequencies. One of the reasons whyprevious attempts at using music have not always been successful may bethe extremely high co-morbidity of high frequency hearing loss withtinnitus.

[0045] Typically, the presence of a sloping high frequency hearing losswould mean that at a relaxing sound volume level, only the low pitchcomponents of the music are heard, and therefore the perception of anymusicality and high frequency available for masking is inhibited. Thelong term spectra of both a music recording and a typical prior arttinnitus masker (a Starkey TM5) are illustrated in FIG. 1. A sound levelanalyser was used to average the response of each of the two recordingsover a 64 second period. The spectra were then matched at 1 kHz toenable a comparison of the frequency composition of the two spectra,irrespective of overall sound pressure-levels. As can be seen from FIG.1, if the masker is assumed to be the optimal frequency response forhearing impaired listeners, then the unfiltered music has insufficienthigh frequency energy and excessive low frequency response. Therefore,the present inventor has developed a tinnitus masking protocol whichmodifies the frequency response characteristics of an audio signal witha view to overcoming some of the shortcomings of traditional tinnitusmaskers.

[0046] Although the following description will be made primarily withreference to modifying the frequency response characteristics of music,it is to be understood that a tinnitus masking protocol in accordancewith the invention may also be applied to other types of audio signalsuitable for masking of tinnitus, or for providing auditory stimulationfor tinnitus and hypercusis therapy without masking. Furthermore, inview of the relatively high cost of traditional hearing aid-stylemaskers, the following description will give particular emphasis to theuse of conventional, insert or wireless headphone systems or insert typeheadphones in conjunction with a suitable personal sound reproductionsystem such as a high fidelity personal music player (PMP) for audiocassette, CD or MP3 recordings. In Australia, the retail cost of a highfidelity PMP is around one-tenth the cost of conventional binauralmaskers. However, it is to be understood that the tinnitus maskingprotocol according to the invention may also be applicable toconventional hearing aid-style maskers. The technique can also beapplicable to the setting of additional user programs in hearing aids,or the modified signal may be transmitted to the tinnitus suffererthrough their hearing aids' telecoil or induction coil facility.

[0047] In addition to the low cost and high portability of PMPs, theygenerally possess small headphones with long-throw transducers thatenable far superior fidelity compared to most free field loudspeakersystems. Furthermore, headphones are generally more effective than loudspeakers because they circumvent the extensive attenuation of highfrequency sounds that occurs through a free field. Changes in PMPearphone position on the pinna have been shown to have very limitedeffects on the spectral composition of toned sweeps measured in a KEMAR(Knowles Electronic Mannequin for Acoustic Research).

[0048] In developing a tinnitus masking protocol, the required extendedupper frequency stimulus presented challenges for the conversion ofaudiogram results to the required real ear response, given that thereare as yet no internationally agreed-upon standards for the conversionbetween dB HL to dB SPL for 10 and 12 kHz pure tone and narrow bandnoise stimuli. The manufacturer's calibration specifications for aMadsen OB 822 audiometer were used to extrapolate the required valuesfor use with a telephonics TDH 39 headphones and MX 41/AR cushions. Theaudiometer was professionally calibrated accordingly. The values for 10kHz were 50 dB HL=59.5 dB SPL and at 12 kHz, 50 dB HL=61 dB SPL. All ISOhearing level frequencies below 10 kHz were calibrated as per therelevant Australian standards (AS 1591.2-1987). Table 1 lists thetransfer/calibration values in inverted format used for converting dB HLto dB SPL. TABLE 1 Frequency kHz 0.25 0.5 1 1.5 2 3 3 6 8 10 12 dB 25.511.5 7.0 6.5 9.0 10.5 10.5 16.5 12.0 9.5 11.0

[0049] A further feature of the first tinnitus masking protocol (TMP1)developed by the inventor, was an adaptation of the half gain rule,whereby amplification for hearing loss is most effective when itcompensates for only around one half of the hearing deficit. This ruleunderlies most current hearing aid prescriptive practices. The TMP1attempted to maximise the acoustic energy centred around the pitch ofthe individual's tinnitus, and to “balance” the headphone output tocorrect for any asymmetrical hearing loss. A further goal was to enablethe balanced perception of the masking stimulus throughout the person'shead, rather than at the ear level like traditional uncorrelatedtinnitus maskers.

[0050] All PMPs have a volume control range that far exceeds what isavailable in hearing aids, and so the TMP1 did not need to specifyabsolute gain figures. However, PMPs generally do not possess aleft/right balance control, and this was expected to reduce theiracceptability in cases of asymmetrical hearing loss and its associatedloudness recruitment As the TMP I formulae aimed to minimise theperceptual loudness of the music or noise required to mask anindividual's tinnitus, it thus only needed to specify the relativefrequency response characteristics for each ear when presented in thosereproduction systems that do not provide individual control of eachstereo channel.

[0051] The procedure for applying the TMP1 was thus as follows:

[0052] (i) The individual's pure tone hearing level thresholds at eachfrequency were converted to dB SPL by the addition of the transfervalues in Table 1.

[0053] (ii) The tinnitus pitch match frequency in the most severelyaffected ear was chosen for the maximal point of the base linecalculation. The two adjacent best hearing thresholds of the lesserhearing loss ear was always chosen as the minimum point of thecalculation. When a reliable pitch match was not found using pure tones,it was substituted with the mean of the two adjacent best hearingfrequencies. Thus, the base line constituted a mid line value betweenthe two greatest audiometric extremities.

[0054] (iii) The final equalisation values were then derived bysubtracting the base line from the hearing threshold (expressed in dBSPL) for each frequency and each ear. Thus the algorithm for patientswhose tinnitus pitch could not be reliably determined was:

Baseline=0.5(A−B)+B

Required Equalisation, REQ=0.5{SPL_((0.25,0.5,1,2,3,4,6,8,10,12 kHz))−Baseline}

[0055] The algorithm for non-tonal tinnitus was:

Baseline=0.5(C−B)+B

REQ=0.5 {SPL_((0.25,0.5,1,2,3,4,6,8,10,12 kHz))−Baseline}

[0056] Wherein,

[0057] A=hearing threshold (dB SPL) at frequency of tinnitus pitchmatch.

[0058] B=mean dB SPL at the 2 adjacent least hearing loss frequencies.

[0059] C=mean dB SPL at the 2 adjacent greatest hearing lossfrequencies.

EXAMPLE 1

[0060]FIG. 2 is a graphical representation of the relationship between atypical individual's hearing levels, tinnitus and their required TMP1equalisation curves. This individual has a steeply sloping highfrequency bilateral hearing loss and tinnitus at 10,000 Hz, both greateron the left side. Consequently, the required equalisation curves revolvearound the equaliser's baseline, achieving a partial correction forhearing loss by boosting the amount of high frequency gain and alsocorrespondingly attenuating the low frequencies. As the hearing loss andtinnitus is worse on the left, that ear receives correspondingly greateramplification. Because of the abnormal growth of loudness perceptionwhich usually accompanies sensorineural hearing loss, (recruitment,and/or the presence of hyperacusis), complete correction for hearinglevels is not provided, as this may exceed the individual's loudnessdiscomfort levels.

[0061] A tinnitus rehabilitation sound recording was then produced on anaudio cassette tape for use in the individual's PMP. A stereo frequencyequaliser (Genexxa 31-9082) was used in this procedure, which includesten adjustable frequency bands per channel, with centre frequencies at0.031, 0.062, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16 kHz. Each control had arange of + or −12 dB SPL. The equaliser featured an “EQ record”facility, so that the audio signal could be passed through the equalisercircuit before being recorded. The equaliser's controls for each of theten frequency bands was set to the calculated values for the left ear inthe left channel of the equaliser, and the right ear values set in theright channel, in accordance with the particular individual'sequalisation values as calculated by the TMP1 algorithm. The stereooutput from a broadcast quality cassette recorder was connected to thestereographic equaliser, which then had its output routed to anotherhigh fidelity cassette deck for recording onto high fidelity audiocassette tape. Dual leads and stereo RCA connecters were used topreserve L/R channel separation.

[0062] Modified sound recordings of both music and white noise were madefor use in clinical trials with 30 participants. Each participant wascounselled as to the rationale behind masking therapy and the possiblebenefits of using the tinnitus rehabilitation sound recording. Eachparticipant was issued with a new PMP with standard insert headphones(Sony MDR E552) that fit into the concha and thus do not require aheadband. Sound level-peak analysis measures were then performed. Withtheir custom-made tape playing in the PMP, they were asked to slowlyturn up the volume until they could just no longer perceive their owntinnitus. This level was marked on the volume control wheel. Eachparticipant was told to notify the audiologist if they subsequentlyneeded to turn up the volume further than the marked position. They wereencouraged to experiment downwards with the volume control over thecourse of each masking session, as they might find that they requireprogressively less volume to totally mask if residual inhibitionoccurred.

[0063] One group of participants was given a noise tape whereas theother group was given a music tape. While both treatment groups hassimilar levels of pre-therapy distress associated with their tinnitus,the-music group displayed a much greater improvement by mid-therapy andthese gains were maintained at the two-year post-therapy follow up. Thenoise group also displayed some improvement, but much less dramatic thenthe music group. 96% of the participants found their music or noisetapes to be an effective masker, which is a far higher acceptance ratethan for conventional ear level tinnitus maskers.

[0064] In some cases, the TMP1 appeared to present an unbalancedperception of loudness where the individual possessed a substantialinter-aural asymmetry. The real-ear perception of loudness may havedeviated from the prescribed response due to perception of loudnessdifferences at various points across the frequency range. It was alsothought that the half gain rule for hearing aids might be best suitedfor the moderate hearing loss population, and that a mild hearing lossmight only require one-third gain. Furthermore, it is possible that therecruitment of loudness phenomena might be greater in tinnitus patientsthan non-tinnitus patients, particularly given its high co-morbiditywith hyperacusis and phonophobia (the fear of external sounds). Thesefactors suggested that the TMP1 might be overcompensating for hearingloss, and that further modifications were required to optimise theprocedure.

[0065] The main purpose of the TMP1 algorithm was to produce anacceptable substitute for the tinnitus at the lowest possible. MML andto accommodate for any interaural symmetries. However, it wassubsequently realised that an improved masking algorithm would be morerobust if the prescription of the required equalisation response wasperformed solely on the basis of maximum and minimum hearing levels, andthereby attempt to provide relatively equal sensation levels at allfrequencies. Data from the TMP1 study indicated that 44.4% of the musicgroup, and 28.6% of the noise group participants preferred to set thevolume of their audio tapes at a level which only partially masked theirtinnitus. This occurred despite being instructed that the optimalsetting was to totally mask. The differences in masking levelpreferences between the two types of stimuli also suggests that musicwas more acceptable than noise when used at volume levels where thetinnitus could still be partly perceived. Whilst the historical approachhas been to totally mask tinnitus, and the current clinical trend is topartially mask, the present inventor has developed an improved tinnitusmasking protocol based on intermittent masking. Since music is a highlydynamic signal, it appears possible that the intensity of music whichpartially masks might actually constitute a form of intermittentmasking. A schematic representation of intermittent tinnitus maskingusing a music signal is illustrated in FIG. 3.

[0066] Without wishing to be bound by theory, it is believed that theintermittent masking of tinnitus with a relaxing stimulus (such asmusic) may be effective on a psychological, as well as on an acoustic orneural level. In theory, it is feasible that intermittent tinnitusmasking with music might constitute a form of systematicdesensitization. Whilst in a relaxed state, the listener might bealternatively perceiving, then not perceiving the tinnitus, according tothe fluctuations in the peak levels of the music. The predicability ofthe music may mean that the tinnitus might not even be consciouslyperceived during the “troughs” of the music. Additionally, the tinnitusmight “reappear” from the music often enough for habituation to occurBut the ongoing dynamic nature of the music signal prevents this limitedexposure from being disturbing, and this may reduce any limbic systemenhancement Thus, the proposedintermittent-masking-with-relaxation-music technique may promote asynergetic effect through its additional mechanisms of facilitating asense of control, a reduction in general anxiety levels, and a form ofauto-hypnosis leading to a reduction of fear about the tinnitus itself.Therefore, an improved masking algorithm based on a tinnitus retrainingprotocol (CRP) was developed that was designed to produce intermittentmasking of the tinnitus.

[0067] In practice, the TMP1 algorithm's use of the half-gain ruleappeared to overcompensate for hearing loss as noted above, sometimesmaking the recording seem unbalanced or “tinny”. Conversely, there wereseveral factors that suggested that the one-third rule might not providesufficient equalisation. The long term music spectrum has considerablyless high frequency energy than what is typically available fromconventional tinnitus maskers, and yet the greatest hearing loss istypically concentrated in this region (see FIG. 1). Therefore, anysubstantial reduction of gain could prevent achieving adequate highfrequency equalisation to overcome the limitations in the music spectraand the effects of hearing loss. Therefore, because the half gain rulewas sometimes excessive, but one third gain may be insufficient for thepurposes of modifying music for long term tinnitus retraining, a mediumselected by the incorporation of a 0.4 gain multiplier, (M).

[0068] To further facilitate the provision of equal sensation levels ofmusic across the full spectral range of the music signal, the improvedTRP algorithm adopted the ISO Equal Loudness Contours (ELC). The ELCtransfer values correct for any differences in loudness perceptiondepending on the discreet frequencies (International StandardsAssociation, 1961). The 40 phon contour curve was selected because theearlier study found that the mean participant's customised musicrecordings, under total masking conditions, displayed a RMS of 45.7 dBSPL. Thus, with 8 dB representing an approximate doubling of perceivedloudness, 37.7 dB was extrapolated to be the midpoint between thethreshold and total masking, and thus representative of the intensityaround which intermittent masking would occur with those with a mild tomoderate sloping hearing loss. The 40 phon contour was thus utilisedbecause it was the closest to this mid point, and choice of the lowervalue curve also helped compensate for loudness recruitment.

[0069] The standard audiometric procedure is to obtain hearingthresholds using TDH 39 headphones, and the results are expressed in dBHL (Hearing Level). However, the convention for specifying hearing aidcharacteristics is to utilise dB SPL (Sound Pressure Level) values.Consequently the hearing thresholds (dB HL) obtained in the 6 cm³headphones need to be converted into dB SPL by the addition of thetransfer values in Table 1.

[0070] These transfer values were then summated with the 40 Phon contourvalues. The resulting transfer/calibration values are displayed in Table2. TABLE 2 Frequency kHz .25 .5 .75 1 1.5 2 3 4 6 8 10 12 Corrections23.5 7.5 5.5 7 6.5 7 5.5 2.5 16.5 21 16.5 13

[0071] The tinnitus retraining protocol (TRP) algorithm is amodification of the TMP1 algorithm given on page 10 above, and is asfollows:

REQ=0.4 {ELC+SPL_((0.25,0.5,1,2,3,4,6,8,10,12 kHz))−Baseline}

Where: Baseline=0.5(A−B)+B

[0072] A=mean dB SPL at the two adjacent greatest hearing lossfrequencies in the greatest hearing loss ear.

[0073] B=Mean dB SPL at the two adjacent least hearing loss frequenciesin the least hearing loss ear.

[0074] SPL=hearing thesholds (in dB HL), converted to dB SPL.

[0075] ELC=transfer values for 40 Phon Equal Loudness Contours.

[0076] Alternatively, the patient's hearing thresholds may be obtainedusing ⅓ octave narrow band noises, and the gain multiplier (M) becomes0.7 (or between the range of 0.5 to 0.95).

[0077] The procedure for applying the TRP was as follows:

[0078] (i) The person's audiogram was perused to ascertain the twoadjacent greatest hearing loss frequencies in the greatest hearing lossear (A), and also the two adjacent least hearing loss frequencies in theleast hearing loss ear (B).

[0079] (ii) These four dB HL values were then converted to dB SPL by theaddition of the transfer values in Table 1 (on page 9).

[0080] (iii) The dB SPL mean of the two adjacent greatest hearing lossfrequencies in the greatest hearing loss ear (A) was then calculated indB SPL, and the procedure repeated for the two adjacent least hearingloss frequencies in the least hearing loss ear (B).

[0081] (iv) A midline value was then calculated by the subtraction of Bfrom A, which value is then halved, and the result added to the B value.This is the TRP baseline.

[0082] (v) All of the dBHL thresholds from the audiogram were then addedto the values in Table 2 above which is the summation of the ISO 40 PhonELC correction values, and the dB HL to dB SPL transfer functions. Thisproduces a measure of hearing in terms of the relative perceivedloudness of stimuli at each of the discrete frequencies. The values wereexpressed in dB SPL so that the desired equalisation frequency responsecould be determined within the 24 dB SPL range of the graphic equaliser.

[0083] (vi) The baseline value was then subtracted from each transformedthreshold, and its result then multiplied by the 0.4 gain rule. Thisprocess is repeated for each frequency of each ear.

[0084] (vii) These values were then used to manually set the graphicequaliser with the left ear's required equalisation response (REQ) usedin the left channel, and the right ear's REQ used in the right channelof the equaliser.

EXAMPLE 2

[0085] The audiogram for the participant chosen to demonstrate how theTMP1 accounts for a steeply-sloping asymmetrical hearing loss (seeExample 1 above), was also chosen to demonstrate how the TRP algorithmmodifies the intensity of the audio signal at selected frequencies toprovide intermittent masking of the tinnitus. Tables 3 and 4 below showthe calculations at each frequency for the left and right earsrespectively using the TRP algorithm above. The baseline calculation wasmade as follows: $\begin{matrix}{{Baseline} = {{0.5\quad \left( {A - B} \right)} + B}} \\{= \left\lbrack {{0.5\left( {{L\quad {SPL}_{10}} + {L\quad {SPL}_{12}}} \right)} - {0.5\left( {{R\quad {SPL}_{0.5}} + {R\quad {SPL}_{0.75}}} \right\rbrack \times}} \right.} \\{{0.5 + {0.5\left( {{R\quad {SPL}_{0.5}} + {R\quad {SPL}_{0.75}}} \right)}}} \\{= {\left\lbrack {{0.5\left( {89.5 + 91} \right)} - {0.5\left( {1.5 + 8.5} \right)}} \right\rbrack \times}} \\{{0.5 + {0.5\left( {1.5 + 8.5} \right)}}} \\{= {{\left( {90.25 - 5} \right) \times 0.5} + 5}} \\{= 47.625}\end{matrix}$

TABLE 3 Corrections and Calculations ELC & SPL L Freq. P's P's transfer(Hz) dB HL SPL = functions = −Baseline = × 0.4 = REQ 250 5 23.5 28.547.625 −19.15 × 0.4 −7.66 500 −10 7.5 −2.5 47.625 −50.15 × 0.4 −20.06750 2.5 5.5 8 47.625 −39.65 × 0.4 −15.86 1000 15 7 22 47.625 −25.65 ×0.4 −10.26 1500 25 6.5 31.5 47.625 −16.15 × 0.4 −6.46 2000 40 7 4747.625 −0.65 × 0.4 −0.26 3000 65 5.5 70.5 47.625 22.85 × 0.4 9.14 400060 2.5 62.5 47.625 14.85 × 0.4 5.94 6000 60 16.5 76.5 47.625 28.85 × 0.411.54 8000 60 21 81 47.625 33.35 × 0.4 13.34 10000 80 89.5 16.5 96.547.625 48.85 × 0.4 19.54 12000 80 91 13 93 47.625 45.35 × 0.4 18.14

[0086] TABLE 4 Corrections and Calculations ELC & SPL R Freq. P's P'stransfer (Hz) dB HL SPL = functions = −Baseline = × 0.4 = REQ 250 2023.5 43.5 47.625 −4.15 × 0.4 −1.66 500 −10 1.5 7.5 −2.5 47.625 −50.15 ×0.4 −20.06 750 0 8.5 5.5 5.5 47.625 −41.12 × 0.4 −16.85 1000 5 7 1247.625 −35.65 × 0.4 −14.26 1500 0 6.5 6.5 47.625 −41.15 × 0.4 −16.462000 15 7 22 47.625 −25.65 × 0.4 −10.26 3000 45 5.5 50.5 47.625 2.85 ×0.4 1.14 4000 30 2.5 32.5 47.625 −15.15 × 0.4 −6.06 6000 30 16.5 46.547.625 −1.15 × 0.4 −0.46 8000 20 21 41 47.625 −6.65 × 0.4 −2.66 10000 6016.5 76.5 47.625 28.85 × 0.4 11.54 12000 75 13 88 47.625 40.35 × 0.416.14

[0087] The REQ equalisation curves for both ears are illustratedgraphically in FIG. 4. A comparison of FIG. 4 with FIG. 2 will confirmthat the patient's right and left hearing thresholds [HTL(SPL)] curvesare identical.

[0088] A second clinical study was conducted in which 90 people whosuffer from tinnitus participated. The participants were allocated withblock randomization into one of four treatment groups: one group to testa second generation total masking algorithm (TMP2), one to test thetinnitus retraining algorithm (TRP), one to empirically measure thecurrent TRT approach of using low-level broadband noise stimulants, anda quasi-control group to receive counselling alone. The second studyexceeded expectations, with dramatic levels of habituation experiencedby more than three-quarters of the participants using spectrallymodified music. The adoption of bibliotherapy and TRT-style counsellingresulted in significant improvements in clinical outcomes for alltreatment groups. However, counselling alone appeared to be insufficienttreatment for most participants. An important finding was that the TRPgroup experienced the greatest mean improvements in tinnitus distress.The TMP2 stimulus group initially displayed a more rapid improvement,but the more gradual gains of the TRP group were sustained for longer,and ultimately were superior. There was little difference between thenoise and counselling alone groups at post therapy and follow-up,although the mean improvements experienced by the counselling alonegroup were ultimately not statistically significant. While all treatmentgroups recorded mean reductions in tinnitus distress over therapy, thetwo music groups ultimately appeared to be the most effective.Approximately three-quarters of the two music group participantsexperienced significant habituation to their tinnitus (TMP2=78.6%,TRP=75%).

[0089] There were substantial reductions in hyperacusis scores for bothmusic groups, and a slight reduction for the noise group. The groupwithout acoustic stimulation (Counselling-only) displayed an increase inhyperacusis over the same period, strongly indicating that the provisionof acoustic stimulation was a key ingredient in the hyperacusisimprovements. The music group participants often reported that theirhyperacusis levels tended to improve faster than their tinnitusperception.

[0090] The clinical studies therefore suggest that total masking withmusic is more effective to facilitate a rapid improvement in distressand relaxation levels, despite the fact that intermittent masking withmusic eventually proved to be more effective on several measures. Thisindicates that a two-stage approach might be most efficient, wherebypatients initially should employ a total masking algorithm to give astronger sense of relief and control, then later switch to intermittentmasking to remove the tinnitus detection.

[0091] In the clinical studies, pre-recorded music was spectrallymodified using the predetermined masking algorithms, and re-recorded onaudio cassette tapes for participants' use. This approach is unlikely tobe acceptable for widespread clinical use, in view of the potentialcopyright infringement problems in some states or countries. Purchase ofthe rights to re-record music from selected recording companies is onemeans of circumventing this, or the commissioning of recordingsspecifically for this purpose. In one embodiment it is proposed toprovide a programmable “black box” device for use by privatepractitioners. The device thus envisaged can be programmed by aqualified audiologist to account for each individual's tinnitus andhearing loss characteristics, using the tinnitus masking algorithms andclinical protocols developed by the inventor. In one embodiment, thedevice may take the form of a musician's hearing aid-type devicedesigned to spectrally modify the audio signal as it enters the wearer'sears. A more preferred embodiment is to provide the device in the formof a “black box” which can be employed in conjunction with a PMP and hasan input adapted to connect to the audio output headphone jack on thePMP. The device would have a standard headphone jack to which aconventional PMP headphone can be connected. In an alternativeembodiment, a modified sound recording is automatically generated in theaudiologist's clinic, tailored to the patient's audiometricconfiguration, using software accessed via the World Wide Web.

[0092]FIG. 5 illustrates in schematic block diagram form a possibleembodiment of a tinnitus rehabilitation “black box” device. The device10 has an input 12 adapted to receive a two-channel stereo signal fromthe headphone output jack of a PMP. The device 10 also has an output 14which provides a two-channel stereo signal, spectrally modified by apredetermined masking algorithm programmed into the device 10, which issuitable for listening to through a conventional PMP headphone.Preferably, the device 10 employs digital signal processing, andtherefore the left and right input audio analog signal is converted todigital format in an analog to digital converter (ADC) 16. The digitaloutput signal of ADC 16 is then sent to a digital filter 18 whichfilters the digitised audio signal in accordance with a predeterminedmasking algorithm. The digital filter 18 modifies the intensity of theaudio signal at selected frequencies in accordance with the maskingalgorithm.

[0093] The filter characteristic of the digital filter 18 may beprogrammed manually using thumbwheels. However, more preferably thedigital filter 18 is programmed electronically by means of amicroprocessor-based controller 20 having a communications port 22 thatmay be connected to a desk top computer. Using a custom-designedsoftware program which accompanies the device 10, an audiologist orother hearing aid dispenser can program the device 10 by means of agraphic user interface (GUI) which facilitates the input of the requiredclinical data into the non-volatile memory of the controller 20. Thus,for example, the clinical audiologist would simply enter the patient'spurr tone hearing level thresholds at each of the 10 discretefrequencies from 0.25 to 12 kHz. The audiologist may also be required toenter the two adjacent least hearing loss frequencies (B) the hearingthreshold at the frequency of tinnitus pitch match (A) and/or the twoadjacent greatest hearing loss frequencies (C). Either the software orthe controller 20 will then use these figures to calculate the baselinevalue, and employ the predetermined masking algorithm to calculate therequired equalisation values. These values are employed by thecontroller 20 to set the filter constants at each frequency in thedigital filter 18.

[0094] The device 10 may also include an additional signal processingmeans 24, which is also under control of the controller 20, forproviding further spectral modification of the digital audio signalafter filtering by the digital filter 18. The spectrally modified audiosignal is then converted back to analog format in a digital to analogconverter (DAC) 26. An amplifier 28 may be provided to control theamplitude of the analog output signal provided at the output 14 of thedevice. It will be understood that each of the digital components of thedevice 10 may be integrated into a single integrated circuit, so thatthe dimensions of the device 10 can be made quite small and the devicetherefore remains inconspicuous.

[0095] Further investigation has revealed that the proprietaryalgorithms or digital processing of the audio signal may be entirelysoftware-based, facilitating the production of a stored music medium(compact disc or alternative format) for playback by the tinnitussufferer on a standard personal sound reproduction system, such as apersonal music player (PMP), with headphones. In this embodiment, themethod of providing a tinnitus rehabilitation sound recording takes fulladvantage of the speed and economies provided by the Internet for fastdigital communications and remote processing power. With no more than adesktop personal computer (PC) with CD-writing capability, the abilityto provide a customised tinnitus rehabilitation sound recording can beplaced at the fingertips of the audiologist. By utilising the reach ofthe World Wide Web and developing an application service provider (ASP),(also described as “on-line operating software”), the method can beextended to provide tinnitus relief and treatment to a global marke.FIGS. 6 and 7 illustrate in flowchart form a preferred method ofproviding a tinnitus rehabilitation sound recording utilising the WorldWide Web and the services of an ASP.

[0096] The process commences in the audiologist's clinic where thepatient consults 100 with the audiologist. The audiologist enters 102the patient's personal details into the appropriate fields in anapplication form located on a proprietary website. The audiologist thenconducts 104 an audiogram on the patient's left and right ears. Theaudiogram is converted into an appropriate digital format and stored 106on the audiologist's PC. The audiologist may then activate 108 theapplication service provider (ASP) via the website, which automaticallyaccesses the patient data, including the digital audiogram, andtransmits it via the website to the ASP.

[0097] Data is received 200 by the ASP and split into left and right earprocessing channels. A central processing server (accessed via the ASP)houses the software containing the proprietary algorithms for convertingthe patient data to a digital filtering format herein referred to as aMasking Profile. This Masking Profile is then transmitted back to theaudiologist's PC. The central processing server uses the digitalaudiogram to determine 202 _(L), 202 _(R) the pure tone level thresholdsat each of the predetermined frequencies for the left and right ears.The software ascertains 204 the two adjacent greatest hearing lossfrequencies in the greatest hearing loss ear, and also the two adjacentleast hearing loss frequencies in the least hearing loss ear. In each ofsteps 206 _(L), 208 _(L), 210 _(L), 212 _(L), 214 _(L), 216 _(L) and 206_(R), 208 _(R), 210 _(R), 212 _(R), 214 _(R), 216 _(R) the tinnitusretraining protocol algorithm is applied to the left ear and right earlevels respectively, as is illustrated graphically in Tables 3 and 4above.

[0098] In steps 218, 220 and 222 the baseline value is calculated, whichis subtracted from each of the transformed threshold values for the leftand right ears at 210 _(L), 210 _(R). The left and right ear RequiredEqualisation Response (REQ) values are then transmitted 224 to theaudiologist's PC via the ASP website. The website, which is visible onthe audiologist's PC, notifies 226 the audiologist that the REQ valuesare being downloaded onto the audiologist's PC, and also prompts 302 theaudiologist to insert a music CD into a CD player connected to the PC.The audiologist is also prompted 304 to insert a blank CD into the CDwriter connected to his PC. It is to be understood that any suitableaudio recording may be employed, preferably a music recording, stored onany suitable storage medium, such as a compact disc, audio cassette orMP3 card. Typically, the patient is offered a choice of music CD's, forwhich the appropriate copyright licence fees have been paid, to be usedas the base recording. An audio software application on theaudiologist's PC accesses 306 the CD recording 308 and stores 310 theaudio data to a file in the memory of the PC.

[0099] Proprietary software accessed by the ASP online reads the audiofiles stored in the PC, splits the signal into left and right stereosignals and converts them to Fast Fourier Transform 312 (FT) format 314.Meanwhile, the REQ data received by the audiologist's PC is allocated316 a channel reference (ie left channel data and right channel data318). The software then converts 320 this left and right channel datainto left and right Masking Profiles 322 respectively. Software providedon the audiologist's PC accesses 324 and applies the Masking Profiles tothe right and left FFT signals for each of the stored songs in order toproduce the left and right channels of the spectrally modified musicsignal. Proprietary software 326 converts 326 the modified left andright signals back to the frequency domain for playback as aconventional audio file. The modified audio files 328, one correspondingto each of the songs on the original music CD, are then utilised 330 bythe CD Writer Software stored in the audiologist's PC, and are writtento a blank CD 332.

[0100] The advantage of using an ASP and the audiologist's PC is thatthe amount of data transmitted and the processing power required by theserver is in relative terms, very low. It is the processing of the audiosignal that requires the bulk of the processing power. Via this modelthat power is housed in the PC of the audiologist instead of the server.Processing time would be negligible and therefore the entire processcould be encompassed in the one patient visit.

[0101] Transmission is either via e-mail using a secure line withencryption or via a password-restricted web page; only qualifiedaudiologists having access. Additional security measures such as‘one-time-only-downloads’ or limiting the time the data is available onthe website are also possible.

[0102] The consultation can easily be held in conjunction with a therapysession with the audiologist, or as part of a coordinated therapy regimeof on-going treatment. Possible revenue streams include the download ofthe proprietary software from the website and a royalty on each datadownload, ie. for each CD made (not per patient, as each patient maywish to modify more than one CD). The Internet website could alsoprovide a number of other services to assist in the relief of andtreatment of tinnitus and hyperacusis. Thus, while music is thepreferred embodiment, CDs can also be produced using noise,environmental sounds, pure tones, or even speech signals if this isstrongly preferred by the sufferer. The more computer-literate suffererscould enter their audiogram details without the help of an audiologist.When the audiologist or hearing aid dispenser does not have a CD burner,facility will be available for the CD to be produced at the ASP or othersite, then posted to the clinic. As the data transmission speed of theInternet significantly increases, facility will be available for theprocessing of the audio signal to be performed within the ASP server ifrequired.

[0103] Now that several embodiments of the tinnitus rehabilitationmethod and device have been described in detail, it will be apparentthat the described method and device for providing relief for personssuffering from tinnitus has a number of significant advantages overprior art techniques, including the following:

[0104] (i) by facilitating the use of a personal music player withrelaxing music, it is much more acceptable to patients than conventionalhearing aid-style maskers;

[0105] (ii) it compensates for high frequency hearing loss whichaccompanies the tinnitus in approximately 80% of cases, thus providingthe broadest spectrum of acoustic stimulation;

[0106] (iii) the masking algorithms developed to spectrally modify themasking/retraining *audio stimuli correct for each individual'sparticular hearing loss configuration as well as accounting for theeffects of loudness recruitment, thus enabling effective stimulation ata relaxing intensity level;

[0107] (iv) intermittent tinnitus masking with music can provide a formof systematic desensitisation to the disturbing effects of tinnitus;and,

[0108] (v) spectrally modified sound recordings produced using themasking algorithms reduce tinnitus distress to the point where it was nolonger significantly interfering with quality of life in more than 75%of trial participants. Significant reductions in MMLs were measured, andhyperacusis levels had significantly improved.

[0109] It will also be apparent to persons skilled in the audiologicaland electronics arts that numerous variations and modifications may bemade to the described method and device, in addition to those alreadydescribed, without departing from the basic inventive concepts. Forexample, a masking algorithm in accordance with the invention may beemployed to set the frequency response of existing tinnitus maskerswhich use bands of noise, rather than music, to achieve similar results.Various types of noise, pure tones and speech could also be used inaddition to music. The same masking algorithms may also be employed inexisting wireless receiver devices, (such as the Starkey Silentia Set),or through hearing aid induction coil systems. Furthermore, themathematical algorithms used for calculating the individual prescriptionof the audio signal may differ from the above described algorithms, andextra sounds may also need to be inserted. However, other embodiments ofthe invention would be consistent with the essential clinical techniquethat is intended to provide a modification of the intensity of audiosignals to account for hearing levels, specifically for the reliefand/or treatment of tinnitus and/hyperacusis. All such variations andmodifications are to be considered within the scope of the presentinvention, the nature of which is to be determined from the foregoingdescription and the appended claims.

1. A method of providing treatment for an auditory system disordercomprising: generating a treatment signal by accentuating frequencycomponents in a signal in a frequency range where a person has deficienthearing and ameliorating any objectionable nature in the treatmentsignal by including coherent signal components within a generallistening range of the person.
 2. The method of providing treatment foran auditory system disorder as claimed in claim 1, wherein anyobjectionable nature in the treatment signal is further ameliorated byattenuating the signal in frequencies where a person's hearing isrelatively less deficient.
 3. The method of providing treatment for anauditory system disorder as claimed in claim 1, wherein the auditorysystem disorder is tinnitus and the treatment signal is a maskingsignal.
 4. The method of providing treatment for an auditory systemdisorder as claimed in claim 3, wherein the treatment signal includes afrequency substantially similar to the tinnitus.
 5. The method ofproviding treatment for an auditory system disorder as claimed in claim1, wherein the treatment signal is a highly dynamic signal whosespectral content and intensity constantly varies over time.
 6. Themethod of providing treatment for an auditory system disorder as claimedin claim 5, wherein the treatment signal is a music signal.
 7. Acomputer readable recording medium on which is recorded a program forcarrying out the auditory system disorder treatment method as defined inclaim
 1. 8. A carrier signal encoded to transmit, via a global computernetwork, a computer executable program for carrying out the auditorysystem disorder treatment method as defined in claim
 1. 9. A method ofproviding treatment for an auditory system disorder of a patientcomprising: exposing the patient to a treatment signal; and manipulatingapplication of the treatment signal to the patient so that the patient'sperception of the auditory system disorder is modified on a neural levelwherein the patient is gradually desensitized to the auditory systemdisorder over time, to thereby habituate the patient to the auditorysystem disorder.
 10. The method of providing treatment for an auditorysystem disorder of a patient as claimed in claim 9, wherein thetreatment signal is specifically tailored to the patient.
 11. The methodof providing treatment for an auditory system disorder of a patient asclaimed in claim 9, wherein treatment signal includes components thatare specifically tailored to each ear of the patient.
 12. The method ofproviding treatment for an auditory system disorder of a patient asclaimed in claim 11 wherein treatment signals are delivered in abinaurally balanced way.
 13. The method of providing treatment for anauditory system disorder of a patient as claimed in claim 9, wherein thetreatment signal is a highly dynamic signal whose spectral content andintensity constantly varies over time.
 14. The method of providingtreatment for an auditory system disorder of a patient as claimed inclaim 13, wherein the treatment signal is a music signal.
 15. The methodof providing treatment for an auditory system disorder of a patient asclaimed in claim 9, wherein the treatment signal includes at least anactive treatment portion which is spectrally modified to patientspecifications.
 16. The method of providing treatment for an auditorysystem disorder of a patient as claimed in claim 9, wherein thetreatment signal includes at least one passive treatment portion suchthat delivery of the active treatment portion is more comfortable to andpossibly not perceived by the patient, whereby the patient becomeshabituated to the auditory system disorder by gradually increasing theexposure to the auditory system disorder during treatment.
 17. Themethod of providing treatment for an auditory system disorder of apatient as claimed in claim 9, wherein the auditory system disorder istinnitus and the treatment signal is a masking signal.
 18. The method ofproviding treatment for an auditory system disorder of a patient asclaimed in claim 9, wherein the treatment signal is a music signal. 19.The method of providing treatment for an auditory system disorder of apatient as claimed in claim 9, wherein the treatment signal accounts fora person suffering from a condition characterized by reduced toleranceto sound.
 20. The method of providing treatment for an auditory systemdisorder of a patient as claimed in claim 19, wherein the conditionincludes hyperacusis.
 21. The method of providing treatment for anauditory system disorder of a patient as claimed in claim 9, wherein thetreatment signal is applied intermittently to the patient to provideactive treatment periods in which the auditory system disorder isactively treated and passive treatment periods in which the auditorysystem disorder may exist but not necessarily be perceived by thepatient.
 22. The method of providing treatment for an auditory systemdisorder of a patient as claimed in claim 9, further comprisingproviding the treatment signal via an external device.
 23. The method ofproviding treatment for an auditory system disorder of a patient asclaimed in claim 22, wherein the external device comprises headphones,earphones or wireless earphones.
 24. The method of providing treatmentfor an auditory system disorder of a patient as claimed in claim 9,further comprising providing the treatment signal via an internaldevice.
 25. The method of providing treatment for an auditory systemdisorder of a patient as claimed in claim 9, further comprisingproviding the treatment signal via a hearing insert.
 26. A method forproviding treatment for a patient's auditory system disorder,comprising: measuring the patient's hearing loss characteristics;calculating an optimal gain for each hearing threshold at each frequencyin each ear; and applying the contour curve to a dynamic input signal toobtain an individually prescribed ideal output signal.
 27. The methodfor providing treatment for a patient's auditory system disorder asclaimed in claim 26, wherein at least a main portion of the outputsignal is centered near a mid point of two extremes of the patient'shearing configuration.
 28. The method for providing treatment for apatient's auditory system disorder as claimed in claim 26, wherein therelevant transform values for dBHL to dBSPL, optimal gain multiplierfunctions, or frequency-dependant loudness weighting curves are takeninto account to provide a balanced perception of the signal in each ear.29. The method for providing treatment for a patient's auditory systemdisorder as claimed in claim 26, wherein the auditory system disorder istinnitus and the output signal is generated by spectrally modifying anaudio signal as it enters the wearer's ears.
 30. The method forproviding treatment for a patient's auditory system disorder as claimedin claim 26, wherein the auditory system disorder is tinnitus and theoutput signal is a masking signal.
 31. The method for providingtreatment for a patient's auditory system disorder as claimed in claim26, wherein the treatment signal is a highly dynamic signal whosespectral content and intensity constantly varies over time.
 32. Themethod for providing treatment for a patient's auditory system disorderas claimed in claim 31, wherein the treatment signal is a music signal.33. The method for providing treatment for a patient's auditory systemdisorder as claimed in claim 26, wherein the centering is bi-lateralcentering and is performed by determining the greatest hearing ear ofthe patient and noting the hearing thresholds at a greatest hearing lossfrequency region; determining the least hearing loss ear and noting thehearing thresholds at the least hearing loss frequencies; andcalculating a midpoint between the two extremes to define a baselinefrom which approximately equal amounts of acoustic energy can be addedor subtracted, thus maximizing usable range while minimizing distortion.34. The method for providing treatment for a patient's auditory systemdisorder as claimed in claim 26, wherein the centering is performed bydetermining the midpoint between the desired ear's worst hearingthreshold region and the same ear's best hearing threshold region, todefine a baseline value from which approximately equal amounts ofacoustic energy can be added or subtracted, thus maximizing usable rangewhile minimizing distortion.
 35. The method for providing treatment fora patient's auditory system disorder as claimed in claim 26, wherein theperception of the signal in each ear is maintained by a correlation intime between two different signals.
 36. A method of treating tinnituscomprising generating a treatment signal by accentuating frequencycomponents in a signal in a frequency range where a person has deficienthearing and which treatment signal includes a frequency substantiallysimilar to the tinnitus.
 37. A method for treating tinnitus as definedin claim 36, further comprising ameliorating any objectionable nature inthe masking signal by including coherent signal components within ageneral listening range of the person.
 38. A method for treatingtinnitus as defined in claim 37, wherein the treatment signal is a musicsignal.
 39. A computer readable recording medium on which is recorded aprogram for carrying out the tinnitus treatment method as defined inclaim
 37. 40. A carrier signal encoded to transmit, via a globalcomputer network, a computer executable program for carrying out thetinnitus treatment method as defined in claim
 37. 41. The method ofproviding treatment for an auditory system disorder of a patient asclaimed in claim 1, wherein the treatment signal accounts for a personsuffering from a condition characterized by reduced tolerance to sound.42. The method of providing treatment for an auditory system disorder ofa patient as claimed in claim 41, wherein the condition includeshyperacusis.
 43. The method of providing treatment for an auditorysystem disorder as claimed in claim 37, wherein the treatment signal isa highly dynamic signal whose spectral content and intensity constantlyvaries over time.